It is always a good idea to switch off any appliance before tinkering with its settings. We will go into more detail about each of these steps to turning off your water. Hot water heater b4 calling plumber...take the upper Walk through shutting off your water heater before you have to; How to turn off water heater breaker . To turn off your water heater, following the following instructions in this video: Find your breaker box and flip the breaker for your water heater or if your water heater has a disconnect switch close to the water heater, simply turn off the switch to turn off power to the water heater. You can also choose to turn off the water heater completely depending on the type of your water heater. Most water heaters have a shut off valve on. And, in some instances, the water heater is already wired in. Keep everything off until you can locate the reason for the problem. With the power off, open the panel to see where the water heater is attached to the...